... I've seen them filled in with a pigmented compound as well as seeing dislarged pigment in the scrimshaw replaced.

I've offered ivories with and without pindot nerveholes in the past and it was usually the examples with the holes that sold first (discounted, of course).

An easy detection method to finding pindot nervholes and hairline cracks in an ivory would be to candle the piece or by holding it up to the sunlight (daylight).

JB